Developing renewable biomass raw materials to replace increasingly depleted petrochemical resources for preparation of chemicals has attracted widespread attention. Poly-3-hydroxybutyrate is intracellular polyester synthesized by many kinds of microorganisms, and exists in microorganisms mainly as a storage material for carbon and energy sources. Poly-3-hydroxybutyrate can realize large-scale industrial production by microbial fermentation, and has become an important renewable biomass resource.
N-butyric acid is an important organic chemical, is for example widely used in perfume synthesis, and is used as a raw material for fine chemical products for synthesis of butyrate and cellulose butyrate. Current industrial production methods of n-butyric acid include fermentation and butyraldehyde oxidation. The fermentation method uses starch or sugar as a raw material to ferment with butyric acid bacteria to obtain n-butyric acid, but it also produces many by-products, and the target product n-butyric acid has low purity, resulting in high separation cost; meanwhile, the yield of n-butyric acid is not high, and a utilization rate of sugar raw material is low. The butyraldehyde oxidation method uses manganese acetate or cobalt acetate as a catalyst to oxidize butyraldehyde with air or oxygen, and after the oxidation reaction, butyric acid is obtained by fractionation. The problem of the butyraldehyde oxidation method is that it requires butyraldehyde which is relatively expensive as chemical raw material and metal manganese or cobalt which is harmful to the environment as catalyst.
Therefore, developing an environmentally friendly method using renewable biomass for preparing n-butyric acid with high yield and high purity has important research significance and application value.